CG17560_in3 generates a mirtron from an alternatively spliced intron. Shown is a multiple sequence alignment and phastCons assessment of conservation (obtained from the UCSC Genome Browser). The splice acceptor used to generate the protein-coding transcript is highly conserved across the 12 sequenced Drosophilids; a different splice acceptor is used to generate the CG17560 mirtron. Small RNA mappings exhibit typical Dicer-1 cleavage patterns, including the generation of rare reads corresponding to the cleaved terminal loop. Other rare reads were not summarized in this schematic. Note the slightly atypical hairpin end of this mirtron, which terminates in a 3-nt 3′overhang. Usage of the mirtronic splice generates a frame-shift, since the typical splice site joins in the +2 coding frame, while the mirtron-spliced site joins in the +1 coding frame.
